proper jetting?

so all i know is how to change the jets, i dont even really know how to change the needle setting. why my dilemma seems to be though, is the jetting. the bike is harder to start than most bikes in my past. it makes decent power up to about 5k and then starts this weird bogging blaring noise and wont go any higher unless i give it less than quarter throttle. so im suspecting jetting is my problem.

i remember wired george ripping me for using too big of mains and pilots, but the only reason i bought said mains and pilots was because another member steered me towards them. so now i come asking again, hoping for better results. im also hoping my gas mileage would better from correct jetting.

so here is my question. i have a 82 750 motor with mikuni bs 34s with pods and a kerker pipe. does anyone have a tried and true main and pilot jet setting for this setup? does it matter that i have gpz cams? cus i do. its ride-able as is, just not as entertaining as it could be. i usually have to downshift to jump it past 5k to get the engine boil until its 9500 rpm redline.

ccentralm wrote:

so all i know is how to change the jets, i dont even really know how to change the needle setting. why my dilemma seems to be though, is the jetting. the bike is harder to start than most bikes in my past. it makes decent power up to about 5k and then starts this weird bogging blaring noise and wont go any higher unless i give it less than quarter throttle. so im suspecting jetting is my problem.

i remember wired george ripping me for using too big of mains and pilots, but the only reason i bought said mains and pilots was because another member steered me towards them. so now i come asking again, hoping for better results. im also hoping my gas mileage would better from correct jetting.

so here is my question. i have a 82 750 motor with mikuni bs 34s with pods and a kerker pipe. does anyone have a tried and true main and pilot jet setting for this setup? does it matter that i have gpz cams? cus i do. its ride-able as is, just not as entertaining as it could be. i usually have to downshift to jump it past 5k to get the engine boil until its 9500 rpm redline.

From the symptoms described, I don't suspect the jetting.
Might be the wrong clip position on the jet needle (the long tapered needle from bottom of throttle slide).
The air fuel mixture in carb mid-range is mostly controlled by amount of mixture allowed through the needle jet in which the tapered needle moves up and down.

With a satisfactorily performing engine, the interplay between jet needle and needle jet usually doesn't suddenly go haywire and go from good running to bad running.

Other members will be better able to suggest specific jet sizes to start with toward achieving the "best" jetting for this particular bike and its configuration.

Before addressing the carb jetting, or even addressing the carbs at all, I would assure that compression is adequate (compression test), and that valve clearances are within specs, and observed spark quality is fat-blue, and that ignition timing is correct. and that advancer is functioning properly (may need lubing or both cleaning and lubing).

After other components are addressed, when resorting to carbs, would first assure adequate clean fuel supply and perform clear tube test to assure float bowl fuel levels are within spec.

Correct jetting depends on all this other stuff being first assured within specs.

In the situation at hand, 'betcha it's not the jetting.

Good Fortune!

Patton wrote:

Before addressing the carb jetting, or even addressing the carbs at all, I would assure that compression is adequate (compression test), and that valve clearances are within specs, and observed spark quality is fat-blue, and that ignition timing is correct. and that advancer is functioning properly (may need lubing or both cleaning and lubing).

In other words... :laugh: GET A MANUAL! <-- THE best advise.

There is a ton of rutine maintenence stuff for these bikes, and most of it is detrimental to the running health of the engine.

Compression. valve clearances, and timing chain tension are super important.
Correct spark timing, advancer function, ignition performance (coils, wires, plugs/caps, ignighter, pickups, wiring).
Carburetors must be clean, jetted very close to correct, and installed air tight, and absolutely no air leaks from airbox to exhaust.

There's lots more, (charging system) but if you take a few days with the manual and check over everything it will likely solve your problem, and also give you peace of mind.

BOL!

everything you need....

kzrider.com/index.php?option=com_docman&...d&gid=461&Itemid=108

great advice! i already own a factory manual. the only problem is the carbs arent what came stock with this bike.

i havent read the zip file yet, OMR, but it looks promising!